#include<stdio.h>
#pragma warning(disable:4996)
int main()
{
	int n, h, m;
	int temp = scanf("%d %d %d", &n, &h, &m);
	while (temp != EOF)
	{
		if (m % h != 0)
		{
			int left = m / h + 1; printf("%d", n - left);
		}
		else { int left = m / h; printf("%d", n-left); }
		break;
	}
	
	return 0;
}